Indian hawthorn plant named &#39;rutrhaph1&#39;

ABSTRACT

A new and distinct cultivar of hawthorn,  Rhaphiolepis umbellata,  which is characterized by unique undulate leaf margins with small leaf margins; petite petals, with both length and width being small; overall plant height and width resulting in a small and wide appearance; relatively few stamens; relatively early full bloom date; and relatively slow growth.

BOTANICAL CLASSIFICATION

Rhaphiolepis umbellata

VARIETAL DENOMINATION

Hawthorn ‘RUTRHAPH1’

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of theornamental dwarf evergreen shrub Rhaphiolepis umbellata, known commonlyas Indian Hawthorn, and hereafter referred to by the varietaldenomination ‘RUTRHAPH1’. In the landscape, ‘RUTRHAPH1’ can be used forfoundation plantings, mass plantings, and in large containers. The plantis suited for low maintenance landscapes and performs well in coastalareas as well on dry and sandy sites.

The original plant of ‘RUTRHAPH1’ (originally designated “RA96UM-1”) wasgrown from seed of open-pollinated R. umbellata ‘Minor.’ The seed wascollected in 1996 from a field trial conducted in Tifton, Ga.

Seed were germinated at the University of Georgia and liners were grown.In 1997, the liners were taken to Wight Nurseries in Cairo, Ga., andwere grown under customary production conditions.

‘RUTRHAPH1’ was selected in 1998 for further evaluation. In autumn of2001, ‘RUTRHAPH1’ was planted in the field at the University of Georgia,Tifton Campus, for further evaluation. In May, 2004, semi-hardwoodcuttings were collected, treated with a 1:5 dilution of Dip N' Grow (DipN' Grow Inc., Clackamas, Oreg.) as a five-second quick dip and plantedin 7.9 cm×7.9 cm plastic pots filled with pine bark and perlite (2:1,v:v) substrate.

Cuttings of ‘RUTRHAPH1’ were placed on a propagation bench in a glassgreenhouse and received a mist frequency of 4 s every 10 min duringdaylight hours. Light exclusion was approximately 70%. Greenhousecontrol temperatures were set as 32° C. (day) and 21° C. (night).Rooting percentage was approximately 90% after 120 days, evidencingsuccessful asexual reproduction of ‘RUTRHAPH1’. The uniquecharacteristics of this new cultivar are stable and reproducedtrue-to-type in successive generations.

SUMMARY OF THE INVENTION

‘RUTRHAPH1’ can be compared to its parent, ‘Minor.’ Table 1 describesthe differences between ‘RUTRHAPH1’ and its parent.

TABLE 1 Comparison of key morphological characteristics, 5 year growth,and disease ratings for Rhaphiolepis ‘RUTRHAPH1’ and R. umbellata‘Minor’ ‘RUTRHAPH1’ ‘Minor’ Leaf margin undulate entire Leaf width (cm)2.0 to 3.0 1.5 to 2.0 Petal length (cm) 0.5 to 0.6 0.7 to 1.0 Petalwidth (cm) 0.3 to 0.4 0.6 to 0.7 Number of stamens 1 3 to 1 8 18 to 20 5year height and width (m) 1.4 × 2.6 1.7 × 2.3 5 year disease rating^(z)1.3 1.5 Full bloom date^(y) March 23 April 2 ^(z)Incidence ofEntomosporium leaf spot evaluated in May from 2003 thru 2007, averagedover five years according to a visual scale from 1 = no disease, 2 = 1%to 25%, 3 = 26% to 50%, 4 = 51% to 75%, and 5 = >76%. ^(y)Average dateof plants in full bloom, 2005 thru 2007.

‘RUTRHAPH1’ is a unique and attractive dwarf evergreen shrub with whiteflowers and excellent disease resistance. Terminal and sub-terminalcuttings can be rooted throughout the year as long as the plants are notflowering and semi-hardwood cuttings are taken. Plants have beensuccessfully grown in container sizes ranging from 2.8 L to 19.6 L.Production time for a 2.8 L container is estimated to be 12 to 18months. ‘RUTRHAPH1’ is slower growing than ‘Minor’.

In the landscape, ‘RUTRHAPH1’ usually blooms around the third week ofMarch in south Georgia. In general, ‘RUTRHAPH1’ blooms seven to 10 daysbefore ‘Minor.’ Pest problems are minimal; no fireblight has been noted,and resistance to entomosporium leaf spot is excellent under fieldconditions. Some late season Cercospora sp. has been noted, butdefoliation is minimal. ‘RUTRHAPH1’ has performed well for several yearsin USDA Hardiness zone 8a (USDA, 1990).

‘RUTRHAPH1’ plants have not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in environment such as light intensity, temperature andcultural conditions, without any variance in genotype.

The following characteristics have been consistently observed over thecourse of several years, and, to the best knowledge of the inventor,their combination form the unique characteristics of ‘RUTRHAPH1’ as anew and distinct cultivar:

1. Unique undulate leaf margins with small leaf margins.

2. Petite petals, with both length and width being small.

3. Overall plant height and width resulting in a small and wideappearance.

4. Relatively few stamens.

5. Relatively early full bloom date.

6. Relatively slow growth.

BRIEF DESCRIPTION OF PHOTOGRAPHS

FIG. 1. A mature plant showing glossy foliage, leaf shape and density of‘RUTRHAPH1’.

FIG. 2. A mature ‘RUTRHAPH1’ in flower, March 2007.

BOTANICAL DESCRIPTION OF THE PLANT

Unless stated otherwise, the botanical description of ‘RUTRHAPH1’ isbased on five-year old plants, grown in full sun to light shade underlandscape conditions in Georgia (USDA Zone 7b). Measurements are basedon the average of 10 to 20 samples, and were taken throughout the maingrowth period, from April through September. Colors are based on TheRoyal Horticultural Society Chart, 2001 edition.

-   Plant: Rhaphiolepis umbellata ‘RUTRHAPH1’ is a woody, evergreen    shrub which should be grown in full sun to light shade under    landscape conditions in Georgia. After five years in the landscape,    ‘RUTRHAPH1’ has a height of 1.4 m and spread of 2.6 m.-   Stems: Stems of new growth are tardily pubescent, hairs being a    greyed-white 156-D. Once the pubescence drops, color of new stems is    a grey-orange 177-A, color of old stems being grey 201-A.-   Leaf: Leaves are alternate, obovate in shape with undulating margins    (FIG. 1), the leaf tip being obtuse and the leaf base is    aequilateral. The leaves on mature shoots range from 3.5 to 5.0 cm    in length, 2.0 to 3.0 cm in width, are thick and glossy and the leaf    margins are slightly crenate to entire. The abaxial venation pattern    of the leaves is reticulate. Adaxial leaf color (Royal Horticultural    Society, 2001) is yellow-green 144-A on new growth and green 139-A    on mature growth, while abaxial leaf color is yellow-green 144-C on    new growth and green 138-B on mature growth. Adaxial venation color    on mature plants is green 143-C, abaxial color is yellow-green    144-D. Petiole length ranges from 0.6 cm to 1.0 cm, petiole width is    0.3 cm and petiole color is green 143-C.-   Inflorescence: Inflorescence a panicle, flowers on a given branch 9    to 13, not all at anthesis at the same time, flowers bisexual.    Flower diameter approximately 2.0 cm. Petal number is five, petal    shape obelliptic, margins entire, petal tip rounded to acute. Length    of petals is 0.5 cm to 0.6 cm with a width of 0.3 cm to 0.4 cm.    Petals (top and bottom) are white 155-D. Number of sepals is five,    lanceolate in shape, margins pubescent with acute sepal tips. Sepal    color initially yellow-green N144-A, turning red-purple 59-B as the    flower matures. Sepals are 0.5 cm in length and 0.2 cm in width.    Flower bud length is 0.5 to 0.6 cm with a diameter of 0.3 cm. Flower    bud shape is oblong to oblanceolate. Stamen number ranges from 13 to    18, anther size being 0.13 cm, anther color is yellow 11-C. Color of    pollen is yellow 9-C. Stigmatic color is yellow-green 145-C. Length    of styles is 0.37 cm, color being yellow-green 145-C.-   Fruit: Fruit a greyed-purple (N186-A) pome, two locules per ovary,    one to two seed per fruit. Fruit diameter is 0.75 to 0.95 cm, fruit    length ˜0.7 cm. Fruit ripening in October in Tifton, Ga. Holotype:    field grown plant, Ornamental Horticulture Research Area, University    of Georgia, Tifton, Ga., Hand and Ruter (VSC). Isotype: NA.-   Seed: Seed color is greyed-orange 176-A, length and width 0.6 cm.

1. We claim a new and distinct variety of Indian Hawthorn plant named‘RUTRHAPH1’ substantially as herein described and illustrated.